The present invention relates to spotting systems and methods pertaining thereto.
Thus, the present invention relates to thin-layer chromatography (TLC) according to which specimens in the form of spots are provided on a suitable precoated thin-layer chromatographic plate or paper.
As is well known, procedures in connection with TLC are utilized for purposes of testing samples such as urine samples.
Conventional procedures of this general type suffer from a number of drawbacks. Thus, there are unavoidable inaccuracies inherent therein, and in addition they are time-consuming and expensive.
According to conventional procedures a dried specimen in the bottom of a beaker has a given amount of solvent added thereto in order to form a solution therefrom, and then at least part of this solution is transferred to a chromatographic paper or plate in order to form a spot thereon. These procedures conventionally require a number of transfer operations during which part of the solution in the beaker is transferred to the chromatographic sheet material, with one quantity of liquid which is deposited on the latter sheet material having additional quantities of liquid added thereto in order to form a spot on the sheet material when the liquid solution deposited thereon dries. During the several transfer operations utilized in connection with providing a single spot, the solution in the beaker continues to evaporate so that the concentration of the solution changes in an uncontrollable manner, so that as a result there are unavoidable inaccuracies inherent in such conventional procedures.
In addition, a number of spots are conventionally provided on a single layer of chromatographic sheet material, and because the deposited liquid for a given spot spreads it is not uncommon for adjacent spots to run into each other, thus creating further inaccuracies.
Moreover, the costs involved in such procedures, particularly the labor costs, render such conventional procedures undesirably expensive.
Attempts have already been made to alleviate the problems inherent in conventional procedures of the above type, and in this connection reference may be made to applicant's earlier U.S. Pat. Nos. 3,758,275 and 3,843,323 which do indeed disclose how it is possible to improve the procedures set forth above. The present invention relates to a further improvement over the above conventional procedures.